<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
*{
    margin: 0;
    padding: 0;
}
div{
    margin: 50px auto;
    width: 50%;
    height: 50px;
    border: 2px solid black;
    border-radius: 20px;
    background-color: rgb(71, 81, 88);
}
ul{ 
    display: flex;
    justify-content: space-around;
    align-items: center;
    width: 100%;
    height: 50px;
}
li{
    list-style: none;
}
a{  
    padding: 0 20px;
    height: 100%;
    font-size:18px;
    color: rgb(150, 150, 150);
    text-decoration: none;
}
a:hover{  
    color: white;
    border-bottom:2px solid rgb(128, 108, 108) ;
    transform: all .2s;
}
i{
    display: inline-block;
    font-weight: 500;
    transform:rotate(90deg);
}
div .drop { 
    display: none;
    position: absolute;
    top: 92px;
    left: 43%;
}
div .drop ul{
    display: block; 
}
div .drop ul a{
    display: inline-block;
    padding: 10px 20px; 
    color: rgb(171, 154, 132);
    background-color:rgb(140, 128, 128);
}
div .drop ul a:hover{
    color: white;
    background-color: rgb(71, 81, 88);
    transition: all .4s;
}
/* 状态关联，属性作用于最小及级 */
div .special:hover .drop{ 
    display: block;
}
</style>
<body>
    <div>
        <ul>
            <li><a href="">微信</a></li>
            <li><a href="">程序</a></li>
            <li class="special">
                <a href="">更多<i>></i></a>
                <span class="drop">
                    <ul>
                        <li><a href="">小游戏</a></li>
                        <li><a href="">公众号</a></li>
                        <li><a href="">小程序</a></li>
                    </ul>
                </span>
            </li>
            <li><a href="">介绍</a></li>
            <li><a href="">运用</a></li>
            <li><a href="">数据</a></li>
        </ul>
    </div>
</body>
</html>